This invention relates to a tape feeding apparatus, and more particularly, to an apparatus for feeding a tape bearing repeating patterns printed thereon to a subsequent working station, for example, a cutting machine operating at a constant rate.
Conventional well-known tape feeding apparatus generally feed a tape from its roll at a constant speed for the purpose of printing or cutting. Such feeding apparatus generally use a drum adapted to rotate at a constant speed to pull the tape.
Generally, a tape is fed at a constant speed to a cutting machine operating at a constant rate where the tape is cut into sections of an equal length. However, a problem arises when a tape has a series of repeating patterns printed thereon before it is fed to a cutting machine operating at a constant rate where it is cut into sections each bearing one printed pattern. (Pattern-bearing sections may be used as labels, for example.) In such a case, however, constant feeding of the tape is undesirable because individual pattern-bearing sections of the tape are not exactly equal in length.
The factors causing variations in length of individual pattern-bearing sections are accumulation of slight errors of the position of patterns on the tape during printing, accumulation of expansion and/or shrinkage of the tape itself during printing, elongation of the tape resulting from high speed feeding under increased tension, influence of humidity, conditions under which the roll of tape is stored, slippage of tape and interference by the roll of tape occurring when the tape is taken out, and the like. The difference between two pattern-bearing sections adjoining each other or spaced apart a few sections is, of course, almost negligible or very slight while a considerable difference is found between two sections spaced at a distance. Under these circumstances, if the tape is fed at a constant speed and cut to an equal fixed length, the actual position of cutting will accumulatively deviate from the desired cutting position just intermediate the adjacent patterns.
Therefore, an object of the present invention is to provide a variable speed tape feeding apparatus wherein a tape having a series of repeating patterns printed thereon is fed at a high speed and accurately one by one pattern to a cutting machine operating at a constant rate.